making sequential subsets of a ppp object, based on value of a mark
Ah, it's split(), of course. That was silly of me. --Chris Ryan
Christopher W. Ryan wrote:
I have a marked ppp object, about 5300 points. One of the marks is called period and has values 1:13. What is an efficient way to make 13 period-specific subset point patterns? All I've been able to come up with, embarrasingly, is 13 lines like the following: per1.ppp <- subset(analytical.ppp, subset = (period == 1)) pre2.ppp <- subset(analytical.ppp, subset = (period == 2)) per3.ppp <- subset(analytical.ppp, subset = (period == 3)) and so on. I'm sure there is a better way. Thanks. --Chris Ryan